Resistance rail welding device with alignment mechanism

ABSTRACT

A device for welding together elongated work pieces such as railroad track, is provided with controls to eliminate pre-existing angles that exist between each work piece prior to joining.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device for welding together a firstelongate work piece, such as a first rail, with a second elongate workpiece, such as a second rail, end to end, by means of butt-weldresistance welding, particularly flash welding. The device comprises astructure and a carriage movably connected to the frame structure andslidable with respect thereto in the longitudinal direction of the workpieces, a first clamping device mounted on the frame structure or onparts associated therewith to fixedly clamp the first work piece, asecond clamping device mounted on the carriage to fixedly clamp thesecond work piece, electrodes mounted on the frame structure and thecarriage or on the clamping devices to heat the work pieces to thedesired welding temperature, and a press element to press the facingends of the heated work pieces against one another in the longitudinaldirection of the work pieces to form a bonding welding joint.

2. Discussion of the Prior Art

One problem found in the use of a device of the above-mentioned kind forwelding together for example a number of separate rails to form one longcontinuous rail is to ensure that each welding joint between twoadjoining rails possesses a sufficiently high breaking strength and thateach rail is securely welded in such a position that the upper part ofthe continuous rail thus formed, i.e. the so called rail head, is givena smooth running surface along its upper face and external flank, the socalled track-forming edges, on which the railroad car wheels travel. Toachieve this aim extremely careful relative orientation of the ends oftwo adjacent rails is required transversally as well as vertically. InEP-0 119 098 is described for instance an alignment apparatus comprisingalignment means for alignment of two adjacent rail ends relatively toone another transversely as well as vertically. The alignment means areremoved prior to the final welding together.

As the ends of the descrete rails usually are not manufactured to such aprecision that their transverse end faces are completely straight andextend in parallel with each other when the work pieces are clamped inposition in the frame and the carriage, it is common practice to subjectthem to a so called pre-flashing treatment prior to the welding-togetherproper in order to remove surplus material for reduction of the spacingbetween the ends. The rail flanks and/or the upper surfaces are noteither manufactured to such a precision as to be completely straight,with the result that also when the work piece clamping members arepositioned in parallel with one another a level running surface may notbe obtained on the head of the finished continuous rail. The situationis further aggravated by the fact that in an area around theinterconnecting welding joint the rail may be slightly deformed in thecourse of the subsequent cooling. Since the short-circuiting risksincrease the larger the surface of contact between the transverse endfaces, the risk of short-circuiting consequently becomes particularlyimminent in the case of rails wherein the end faces are completelyparallel.

Another problem found in several of the welding devices used today, suchas flash welding machines, is the use of a press element in the form ofone large pressure cylinder only, a so called upsetting cylinder, forthe final pressing-together of the work pieces, such as rails, in whichcase molten and oxidised material is squeezed outwards from the facingends of the work pieces while at the same time the material underneathwhich is heated to welding temperature, is welded together. Since inthis kind of welding devices lack of space makes it difficult toposition this pressure cylinder in such a manner that its longitudinalaxis, i.e. centre line, coincides with the longitudinal axes of the workpieces, this kind of upsetting cylinder generates a moment of forcewhich acts on the frame. The moment of force is of considerablemagnitude, although the distance between the pressure cylinderlongitudinal axis and said longitudinal axes is comparatively small,since the press force required to achieve the pressing together is ofconsiderable magnitude. As a result, the welding device must be providedwith a sufficiently large and heavy frame to absorb moments of forcewithout buckling. From e.g. DE-1 068 402 it is already known to positionupsetting cylinders symmetrically on either side of the rails to bewelded together, in order to reduce the bending forces and torsionaltorque exerted on the frame during the upsetting operation. A conditionfor this effect to be obtained is to provide for excellent mechanicallinear guidance, ensuring that the two work pieces are maintained inparallel relationship during the upsetting operation. These upsettingcylinders are controlled in common to provide a parallel movement of theupsetting cylinders. Should the relative heights or lateral extensionsof the work pieces be changed during the upsetting operation, the momentof force of the upsetting cylinders will not be evened out andconsequently the resulting moment of force must be absorbed by theframe, which therefore must be provided with an additional frame part.On the other hand, there is no mention in this patent publication thatthe welding device is configured in a manner allowing it to compensatefor technical manufacturing deficiencies in the rails, such as curvedtrack-forming edges.

A further problem found in prior art welding devices is that they do notoffer any possibility of compensating for the kind of deformation of thewelding joint formed during the welding operation that may be caused bythe very pressing-together of the rail on account of the bending forcesarising during this operation, which deformation may result in anunacceptable welding-together of the two work pieces, despite carefuland accurate alignment of the work pieces prior to the welding-proper.

SUMMARY OF THE INVENTION

One object of the present invention thus is to provide a welding deviceallowing two work pieces to be welded together in an acceptable manneralso when the work pieces are not manufactured to a sufficient degree ofprecision with respect to the appearance of the external faces or theirexternal configuration.

A further object of the present invention is to allow alignment of thework piece ends in such a manner that a straight welding joint may beformed despite any deformation as may arise during the subsequentcooling operation.

A further object of the present invention is to allow the work pieceends to be aligned in such a manner that short-circuiting at thebeginning at the welding-together operation is avoided, also in workpieces the end faces of which are not entirely parallel.

These objects are obtained in accordance with the present invention bymeans of a welding device of the kind outlined in the introduction andwhich device is characterized by at least two actuators which areindividually controllable relative to one another for turning the facingends of the work pieces in such a manner that the transverse axes t₁, t₂and/or the vertical axes h₁, h₂ and/or the longitudinal axes l₁, l₂ ofthe work pieces form an angle α, β, and δ, respectively, between oneanother, or in such a manner that an existing angle α, β, and δ,respectively, formed between the transverse axes, and/or the verticalaxes and/or the longitudinal axes of said work pieces is essentiallyeliminated prior to and/or during and/or after the pressing operation.

Due to the provision of at least two actuators that are individuallycontrollable with respect to one another for adjustment of the facingends of the work pieces it becomes possible to align the work pieces insuch a manner that an acceptable welding joint is obtained, even whenthe work pieces are not manufactured to the desired precision withrespect to their external faces, or when they are deformed during thecooling taking place after the welding-together operation or when thetransverse end faces of the work pieces obtain too high a degree ofparallelism during the preflashing considering the short-circuitingrisk. Owing to the individual control of the actuators it becomespossible either to control two actuators in parallel, i.e. in common,causing the carriage to move relative to the frame in a lengthwiseand/or lateral and/or longitudinal direction, or to control themseparately. If the actuators are operated separately, the facing ends ofthe work pieces may be turned relatively to one another in such a mannerthat the corresponding external faces of the work pieces may be placedlevel with one another, also when the corresponding external face on oneof the work pieces is curved. Owing to this arrangement it becomespossible also to turn two work pieces, such as square rods, the endfaces of which are parallel in principle, in such a manner that thevertical axes of the rods form an angle β relative to each other priorto the pressing operation, whereby short-circuiting in the initialstages of the welding-together operation is avoided. Once thewelding-together has started, the work pieces are turned back over thecorresponding angle to ensure that a straight welding joint is formed.

At least one of the actuators preferably simultaneously serves as apress element. Owing to this arrangement the welding device is able toallow compensations to be made for any undesired misalignment of thework pieces that may arise during the very pressing-together operation.

Preferably, the ends of the upsetting cylinders are pivotally connectedto the frame etc. and to the carriage in separate attachment points,said attachment points being so positioned relative to one another thatthe total moment of force exerted on the frame during the pressingoperation is essentially eliminated. The upsetting cylinders need not,however, be positioned symmetrically in order to be able to essentiallyeliminate the moment of force. This arrangement results in a weldingdevice that does not buckle during the very pressing operation,notwithstanding the comparatively weak structure of its frame structureand consequently the entire welding device may be made less voluminousand thus also becomes less expensive to manufacture.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention will be described in closer detail in the following withreference to the accompanying drawings, illustrating two possibleembodiments of the welding device accordance with the present invention.

FIG. 1 is front view of a stationary welding device in accordance withthe present invention, with a first and a second rail positionedtherein.

FIG. 2 is a lateral view of the device in accordance with FIG. 1.

FIG. 3 section taken on line III--III of FIG. 1.

FIG. 4 is a view as seen obliquely from the front and illustrates amobile welding device in accordance with the present invention.

FIG. 5 is a view as seen straight from the front of the mobile weldingdevice of FIG. 4.

FIGS. 6a-6c are enlarged part views of the rails in accordance with FIG.1 during various stages of the welding operation.

FIGS. 7a-7c are part views similar to FIGS. 6a-6c as seen from above therails.

FIGS. 8a and 8b are enlarged part views of the rails in accordance withFIG. 2.

DETAILED DESCRIPTION OF THE REFERRED EMBODIMENT

The welding device illustrated in FIG. 1 is intended to be used forwelding together two rails 1, 2 at the front rail portions 1a and 2a bymeans of flash welding. By the front end portion is to be understood anarea extending a distance of approximately 10-20 mm into the rails fromthe end face of the respective rail. The device consists of a stationaryframe structure 3 and a carriage 4 movably connected thereto. The frameis provided with clamping dies 5a, 5b in the form of one lower and oneupper die 5a and 5b, respectively, by means of which the rail 1 issecured in the frame 3. The dies are clamped about the rail by means ofa cylinder 6. As appears from FIG. 2, the upper die abuts against theupper face 1b of the rail head and the lower die against the bottom face1e of the rail. The frame is also provided with electrode dies 7 whichare clamped about the rail 1 by means of a cylinder 8 adjacent the railend portion 1a, to supply current for heating said end to the desiredwelding temperature. In a corresponding manner, the carriage 4 isprovided with clamping dies 9a, 9b in the form of one upper and onelower die 9a and 9b, respectively by means of which the rail 2 issecured to the carriage 4. These dies are clamped about the rail bymeans of a cylinder 10. As appears from FIG. 1, the upper die abutsagainst the top face 2b of the rail head and the lower die against thebottom face of the rail. The carriage is also provided with electrodedies 11 which are clamped about the rail 2 by means of a cylinder 12 inthe vicinity of the rail end portion 2a, to supply current for heatingsaid end to the desired welding temperature. Three individuallycontrollable actuators in the form of upsetting cylinders 13, 14 and 15interconnect the carriage with the frame, the cylinder bodies of saidcylinders being pivotally connected to the frame 1 in separateattachment points whereas their associated piston rods 13a, 14a and 15a,respectively, are pivotally connected with the carriage 4, making thecylinder axes pivotable relative to the frame. As appears from FIG. 2,the cylinder 15 is attached to the frame 1 by means of a bracket 15b. Itis also of uttermost importance that the cylinders operate in such amanner relatively to one another that the total torque exerted on theframe 1 during the pressing-together operation is eliminated. As appearsfrom FIG. 2 this is achieved in accordance with the present embodimentby positioning the attachment points, of the cylinders 13 and 14 inalignment in the vertical direction, and equally spaced from thelongitudinal axis 11 of the rail 1, and by positioning the attachmentpoints of cylinders 14 and 15 in alignment, laterally and equally spacedfrom the longitudinal axis 11 of the rail 1. Also other positions of theupsetting cylinders 13, 14 and 15 are acceptable. However, the upsettingcylinders should be positioned to ensure that imaginary linesinterconnecting the cylinder attachment points form a triangle.

As most clearly apparent from FIG. 3 the lower part of the frame 3 isprovided with two parallel legs 16, 17 positioned on either side of thelower part of the carriage 4. Each leg 16 and 17 is formed with itsrespective end-to-end aperture 18 and 19. The lower part of the carriageis provided with an end-to-end aperture 20 in which two shafts 21, 22are received so as to project somewhat beyond the aperture ends. Eachshaft 21, 22 is provided at its outer end with a pin 23 and 24,respectively, said pins being positioned eccentrically with respect tothe shaft center. Each shaft 21 and 22 is provided with a pair ofprojections 25, 26 and 27, 28, respectively, each projection pair beingrotationally connected with an actuator in the form of an actuatingcylinder 29 and 30, respectively, via associated piston rods 29a and 30arespectively. The cylinder bodies of the cylinders are in turn pivotallyconnected to the carriage 4.

As also appears from FIG. 3 each eccenter pin 23, 24 is mounted in itsrespective one of apertures 18, 19 by means of sliding blocks 31 and 32,respectively. The eccenter pins 23, 24 are rotationally connected withthe sliding blocks by means of disk-shaped seats 33 and 34,respectively. As appears from FIG. 1, the apertures 18, 19 areconfigured in such a manner that vertically they are practicallycompletely filled by the sliding blocks whereas in the longitudinaldirection of the rails they are approximately twice as long as thesliding blocks. Consequently, the carriage is displaceble relative tothe frame in the longitudinal direction of the rails and thisdisplacement is effected by the upsetting cylinders 13, 14, and 15.

The carriage is also displacable in the transverse direction of therails by means of a cylinder 35 which is rigidly connected with the leg17 of the frame 3. At its outer end the piston rod 35a of said cylinderis connected with a plate 36 which is positioned in a guide rail 37connected to the carriage 4. The guide rail 37 is formed with a groove37a, and the dimensions of the plate are such that the height of theplate exceeds the width of the groove at the mouth 37aa whereas theplate end portion 36a, which is connected with the piston rod 35a, has asmaller width than the mouth. This arrangement ensures that upondisplacement along the longitudinal axis l₂ of the rail 2 the guiderail-may be displaced relatively to the plate 36 without risking to bedisengaged from the plate.

Drawing FIGS. 6a-6c show only the rails 1 and 2 and the clamping dies5a, 5b and 9a, 9b, respectively, in a lateral view, and the outer flanksof the rail head are designated by 1d for rail 1 and by 2d for rail 2.The upper surfaces 1b, 2b and the flanks 1d, 2d form the track-formingedge faces on which the railroad car wheels travel. In these drawingfigures are also indicated the longitudinal axes l₁ and l₂ of rails 1and 2 as well as the vertical axes h₁ and h₂ and the transverse axes t₁and t₂. By the expressions vertical axes and transverse axes is to beunderstood in the introductory part of the description, the descriptionof the drawing figures, the claims, and the abstract an axis extendingat right angles to the upper face of the associated rail in the frontend part of the rail, and an axis extending at right angles to theexternal flank of the associated rail in the front end part of saidrail, respectively. When the device described above is to be used forwelding together rails 1 and 2, the rails are clamped in position byclamping dies 5 and 9, respectively, which originally are positioned inparallel relationship, see FIG. 6a.

As appears from FIG. 6a the upper surface 1b of the rail 1 is completelystraight, whereas the upper surface 2b of rail 2 is curved. If the railswere to be pressed together while assuming the position illustrated inFIG. 6a the head of the continuous rail thus formed would present acurved running surface along its upper face. This is not acceptablebecause the resulting rail would in this case have to be submitted tocomplicated post-treatment in order to meet the requirements onstraightness in the running surface. To remedy the situation, thecarriage 4 is turned in accordance with the teachings of the inventionand consequently also the clamping dies 9a, 9b as well as the rail 2which is clamped between the dies in the transverse direction t₂ asillustrated in FIG. 6b, in order to compensate for the angle β betweenthe vertical axes in the starting position, see FIG. 6a. The rail 2 isturned by means of the cylinders 13, 14, and 15. The turning movement iseffected by activation of either cylinders 14 and 15 in such a mannerthat their piston rods move at the same relative speed whereas cylinder3 remains inactivated, or else cylinder 13 is activated whereascylinders 14 and 15 remain inactivated. To bring the upper faces 1b, 2bof the rails at the front portions 1a and 2a, respectively, to the-samelevel the clamping dies 9a, 9b, and consequently the rail 2, are turneduntil the vertical axes h1 and h2 become essentially parallel, i.e. theclamping dies 9a, 9b and the rail 2 are turned over angle a asillustrated in FIG. 6b. The alignment of rail 2 relatively to rail 1having been completed, the electrode dies 7 and 11 are activated to heatthe end portions of rails 1 and 2 to the desired welding temperature.The pressure cylinders 13, 14, and 15 are then activated in order toforce the end portions of rails 1 and 2 together to form a bondingwelding joint as illustrated in FIG. 6c.

FIGS. 7a-7c show only rails 1 and 2 and the clamping dies 5a, 5b and 9a,9b, respectively, in a view from above. These drawing figures illustratethe manner in which the flanks 1c, 1d and 2c, 2d, respectively, of rails1 and 2 are displaced to a position in which they are level with oneanother despite the rail 2 having curved and not straight flanks. FIG.7a illustrates the rails 1 and 2 in the position in which they areclamped by the clamping dies 5a, 5b and 9a, 9b, respectively, in theirparallel starting position. FIG. 7b illustrates the rails 1 and 2assuming the position after the clamping dies 9a, 9b, and thus rail 2,having been turned so as to bring the flanks of the front end portions1a and 2a level with one another. In this position the rail 2 has beenturned about its vertical axis h₂ over an angle δ, which is the anglebetween the longitudinal axes l₁ and l₂ of rails 1 and 2, respectively,in the starting position, see FIG. 7a. Like in the previous case, alsoclamping dies 9a, 9b have been turned over this angle from theiroriginal position, see FIG. 7b. This angular adjustment is achieved byactivating either the upsetting cylinders 13 and 14 in such a mannerthat their piston rods move at the same speed relatively to one anotherwhereas the upsetting cylinder 15 remains inactivated, or in such amanner that cylinder 15 is activated whereas upsetting cylinders 13 and14 remain inactivated. The angular adjustment having been completed thevery welding together of the rails 1 and 2 is effected in the samemanner as described in connection with FIG. 6c.

FIGS. 8a and 8b show only the rails 1 and 2 and the clamping dies 5a, 5band 9a, 9b, respectively, as seen in a lateral view, and in order tomake rail 2 visible it is marked by dash-and-dot lines. As appears fromFIG. 8a the rail 2 has both a curved upper surface 2b and a curved web2f. In order to bring both the heads 1b and 2b and the webs 1f and 2f ofrails 1 and 2, respectively, to a position in alignment in front of oneanother rail is turned about its longitudinal axis l₂ over an angle αwhich equals the angle between the transverse axes t₁ and t₂ of rails 1and 2 in the starting position in which the clamping dies 5a, 5b and 9a,9b are oriented in parallel with one another. Like before, the changedposition of the clamping dies 9a, 9b has been chosen to illustrate theangular turning movement over angle α. The turning movement about thelongitudinal axis l₂ of the rail 2 thus makes it possible to compensatefor curvatures in the rail profile. In order to turn the rail 2 aboutits longitudinal axis only one of the actuating cylinders 29 and 30 isactivated, or else the cylinders are activated in such a manner thattheir piston rods move at different speeds relatively to one another.The angular adjustment having been completed, the rails 1 and 2 arewelded together in the manner described previously in connection withFIG. 6c.

Because it is assumed in FIGS. 6a-8b that the rail 1 is completelystraight and that the clamping dies 9a, 9b are positioned in parallelwith clamping dies 5a, 5b in the starting position, the clamping dies9a, 9b will be turned by an amount corresponding to the original angleβ, δ and α between the vertical axes, longitudinal axes and transverseaxes, respectively, of the rails. Obviously, it is likewise possible toturn the rail 2 about its vertical axis h₂, its longitudinal axis l₂ aswell as its transverse axis t₂ before the rail 2 is pressed against rail1 in the longitudinal direction of the upsetting cylinders in order toperform the welding operation proper, should the original externalconfiguration of the rail 2 be of such a nature that an angularadjustment is required in more than one direction in order to obtain astraight running surface. Preferably, the angles α, β and δ are in therange from -5° to +5°, particularly from -2° to +2°.

Since the piston rods of the upsetting cylinders may move also atdifferent mutual speeds during the very pressing operation, it becomespossible to adjust the orientation of the rails with respect to oneanother also during this operation. As a result, the continuous railformed in the welding-together operation will exhibit an even runningsurface on which the railroad car wheels travel. Should the runningsurface of the finished rail, notwithstanding the angular adjustmentsmentioned above made prior to and/or during the very pressing operation,not be completely straight after the welding operation a finaladjustment of the rail 2 may be made with the aid of the actuating andupsetting cylinders before the formed welding joint has hardenedcompletely.

FIG. 4 illustrates a mobile welding device for welding together tworails, only one of which, designated 40, is illustrated in this drawingfigure. This device is intended to be used when it is desired to weldtogether rails in situ on the railroad track. In order to avoid that thedevice becomes too heavy to be moved, its dimensions have been halved,compared to those of the previously described, stationary variety of thedevice. With the exception of the elimination in this variety of astationary frame, it is designed on the same principles as thestationary variety.

This device is provided with two pairs of clamping dies 41 and 42 whichare used to clamp one rail each. Each clamping die pair consists of twoclamping dies 41a, 41b and 42a, 42b, respectively, which dies areclamped about its associated rail by means of cylinders 43 and 44,respectively. The electrodes, not shown, are mounted on the clampingdies in this case. Also in accordance with this embodiment the clampingdie pairs 41 and 42 correspond to the frame 3 and the carriage 4,respectively, according to the stationary variety with the exceptionthat both clamping die pairs are displacable in the lengthwise directionof the rails by means of three pressure cylinders 45, 46, and 47. Thesecylinders correspond to cylinders 13, 14, and 15, respectively, of thestationary device. In this embodiment all upsetting cylinders are,however, positioned above the longitudinal axis l₄₀ of the rail 40. Thisarrangement does not however, give rise to any problems, although thelongitudinal axes l₄₅, l₄₆ and l₄₇ in this case do not coincide with thelongitudinal axis of the rail, since the moment of force of thecylinders 46, 47 is absorbed during the upsetting operation by thecylinder 45, the piston rod of which operates in the opposite directionto that of the piston rods of cylinders 46 and 47.

By the expression individually controllable upsetting or actuatingcylinders should be understood that each cylinder is controlled withrespect to the position of the outer end of its associated piston rod,the outer ends of the piston rods assuming their extreme outer positionsin the starting position. During the angular adjustment and the verypressing-together operation the cylinder piston rods are then caused tomove in a direction towards their innermost positions. Because allcylinders are controlled with respect to their individual positions itis ensured that the cylinder piston rods do not travel neither ahead ofnor lag behind one another. In other words, the frame and the carriagealways assume the same mutual relationship as regards parallelism duringthe entire pressing-together operation, irrespective of where theresistance, i.e. the centre of force of the current work piece, isfound.

In prior-art welding devices the problem has been solved with the aid ofa linearly mounted carriage, or with the aid of levers, or byrelinquishing the requirement of alignment during the pressing-togetheroperation, but a common feature still is that a moment of force must beabsorbed by the frame while the work pieces are being pressed together.As appears from the above description of the welding device inaccordance with the present invention only the forces that will displacethe work pieces laterally and vertically need to be absorbed by theframe in the case of the subject welding device, since the moment offorce generated by the pressing forces essentially has been eliminated.

Obviously, the invention is not limited to the embodiment describedabove but may be modified in a variety of different ways within thescope of the dependent claims. For instance, the upsetting cylinders 13,14, and 15 may be positioned in a Y-shaped configuration instead of theconfiguration referred to above.

Instead of using actuating cylinders 29 and 30 to bring about thelateral and vertical displacement, other positioning means, such as anelectric motor or a set screw may be used. Instead of positioning twoshafts 21, 22 in the bore 20 one shaft may be eccentrically mountedinside the bore 20 and in this case-the vertical adjustment is achievedby turning the shaft, and in order to turn the rail 2 about itslongitudinal axis l₂ eccenter or other resetting means may be providedat the slide blocks 31 and 32.

The work pieces need not consist of two rails 1 and 2 but could consistof two square rods to be welded together by so called upsetting. In thiscase it may be difficult to initiate the very welding process, owing tothe considerable short-circuiting risks with consequential surge, due tothe considerable surface of contact between the rods because their endfaces and consequently their transverse, vertical, and longitudinal axesare parallel in the starting position. For this reason, one work pieceis turned relatively to the other work piece prior to the verywelding-together operation, with the aid of two individuallycontrollable actuators in the form of e.g. two upsetting cylinders ortwo actuating cylinders, the latter cylinder, like in the previous casebeing arranged to turn one work piece about the longitudinal axisthereof. For instance, one work piece is turned in such a mannerrelative to the other work piece that the vertical axes of the workpieces form an angle β between one another. Once the very weldingoperation has started, said work piece is turned backwards over angle βin order to give a straight welding joint.

I claim:
 1. A device for welding together a first longitudinallyelongated work piece with a second longitudinally elongated work piecein an end face-to-end face fashion by means of butt-weld resistancewelding, each of said work pieces having a respective and correspondinglongitudinal, vertical and transverse axis which form respective andpre-existing α, β, and δ angles between the work pieces prior towelding, comprising:a frame structure; a carriage connected to saidframe structure and slidable in the longitudinal direction of the workpieces; a first clamping device mounted on said frame structure tofixedly clamp the first work piece; a second clamping device mounted onsaid carriage to fixedly clamp said second work piece; electrodesmounted on one of the frame structure, carriage, and clamping devices toheat the work pieces to a desired welding temperature; a press elementto force the facing ends of the heated work pieces against one anotherin the longitudinal direction to form a bonding welding joint, whereinsaid press element comprises at least two sets of actuators, each ofwhich are individually controllable relative to one another for turningthe respective facing ends of each of the work pieces in a manner suchthat the pre-existing angles of the transverse, vertical, andlongitudinal axes of the work pieces are eliminated at at least one ofprior to, during, and after a welding operation.
 2. The device asclaimed in claim 1, wherein at least one of the actuators simultaneouslyserves as a press element.
 3. The device as claimed in claim 2, whereinthe predetermined angle with respect to the transverse axis is in therange from -5° to +5°.
 4. The device as claimed in claim 3 wherein therange is between -2° to 2°.
 5. The device as claimed in claim 2, whereinthe predetermined angle with respect to the vertical axis is in therange from -5° to +5°.
 6. The device as claimed in claim 5 wherein therange is between -2° to 2°.
 7. The device as claimed in claim 2, whereinthe predetermined angle with respect to the longitudinal axis is in therange from -5° to +5°.
 8. The device as claimed in claim 7 wherein therange is between -2° to 2°.
 9. The device as claimed in claim 2, whereinthe actuators consist of a first and a second actuating cylinder andassociated piston rods, one end of each actuating cylinder beingpivotally connected to the carriage and wherein said carriage includesat least one shaft extending in an interior of the carriage, said atleast one shaft rotatably connected at one end thereof to an oppositeend of each actuating cylinder, and the other end of said shafteccentrically mounted in a first aperture formed in the frame, thepiston rods of said actuating cylinders arranged to move at mutuallydifferent speeds, whereby the carriage and the second work piece clampedto the carriage are adapted to turn about the longitudinal axis of saidsecond work piece such that the end face of the second work pieceassumes a position relative to an end face of the first work piecewherein the angle formed between the transverse axes of said work piecesis one of a predetermined value and zero.
 10. The device as claimed inclaim 2, wherein each of the actuators are respectively formed by anupsetting cylinder having a body and an associated piston rod, each ofthe cylinder bodies of the upsetting cylinders being pivotally connectedto one of the frame structure and the carriage, each of the piston rodsbeing pivotally connected to the other of said carriage and framestructure, the piston rods of said upsetting cylinders arranged to moveat mutual different speeds, whereby the carriage and the second workpiece clamped to the carriage are adapted to turn about the transverseaxis of the second work piece such that an end face of said second workpiece assumes a position relative to an end face of the first work piecewherein an angle formed between the vertical axes of each of said workpieces is zero.
 11. The device as claimed in claim 2, wherein theupsetting cylinders are pivotally connected at their ends to the framestructure and to the carriage at separate attachment points, said pointspositioned relative to one another such that a total moment of forceexerted on the frame structure during the pressing operation is zero.12. The device as claimed in claim 1, wherein the actuators consist of afirst and a second actuating cylinder and associated piston rods, oneend of each actuating cylinder being pivotally connected to the carriageand wherein said carriage includes at least one shaft extending in aninterior of the carriage, said at least one shaft rotatably connected atone end thereof to an opposite end of each actuating cylinder, and theother end of said shaft eccentrically mounted in a first aperture formedin the frame, the piston rods of said actuating cylinders arranged tomove at mutually different speeds, whereby the carriage and the secondwork piece clamped to the carriage are adapted to turn about thelongitudinal axis of said second work piece such that the end face ofthe second work piece assumes a position relative to an end face of thefirst work piece wherein the angle formed between the transverse axes ofsaid work pieces is one of a predetermined value and zero.
 13. Thedevice as claimed in claim 12, wherein the upsetting cylinders arepivotally connected at their ends to the frame structure and to thecarriage at separate attachment points, said points positioned relativeto one another such that a total moment of force exerted on the framestructure during the pressing operation is zero.
 14. The device asclaimed in claim 1, wherein each of the actuators are respectivelyformed by an upsetting cylinder having a body and an associated pistonrod, each of the cylinder bodies of the upsetting cylinders beingpivotally connected to one of the frame structure and the carriage, eachof the piston rods being pivotally connected to the other of saidcarriage and frame structure, the piston rods of said upsettingcylinders arranged to move at mutual different speeds, whereby thecarriage and the second work piece clamped to the carriage are adaptedto turn about the transverse axis of the second work piece such that anend face of said second work piece assumes a position relative to an endface of the first work piece wherein an angle formed between thevertical axes of each of said work pieces is zero.
 15. The device asclaimed in claim 14, wherein the press element includes a third actuatorformed by a third upsetting cylinder having a body and associated pistonrod, said third cylinder body and piston rod respectively connected tothe frame structure and carriage the same as said first and secondcylinder bodies and rods, the second and the third upsetting cylindersarranged such that at least one of the piston rods is movable at adifferent speed from that of the other two piston rods, whereby thecarriage and the second work piece clamped to the carriage are adaptedto turn about the transverse axis of the second work piece such that theend face of the second work piece assumes a position relative to an endface of the first work piece wherein the angle formed between thevertical axes of each of said work pieces is one of a predeterminedvalue and zero.
 16. The device as claimed in claim 5, wherein thecarriage and the second work piece clamped to said carriage are adaptedto turn about the longitudinal axis of the second work piece such thatthe end face thereof assumes a position relative to the end face of thefirst work piece such that the angle formed between the transverse axesof each of said work pieces is one of a predetermined value and zerowherein the piston rods of the upsetting cylinder units are arranged tomove such that at least one of the piston rods is moved at a differentspeed from that of the other piston rods, whereby the carriage and thesecond work piece clamped to said carriage are adapted to turn about thetransverse axis of the second work piece such that an end face of saidsecond work piece assumes a position relative to an end face of thefirst work piece such that the angle formed between the vertical axes ofeach of said work pieces is one of a predetermined value and zero and toturn about the vertical axis of the second work piece such that saidsecond work piece assumes a position relative to the first work piecesuch that the angle formed between the longitudinal axes of each of saidwork pieces assumes one of a predetermined value and zero.
 17. Thedevice as claimed in claim 16, wherein the upsetting cylinders arepivotally connected at their ends to the frame structure and to thecarriage at separate attachment points, said points positioned relativeto one another such that a total moment of force exerted on the framestructure during the pressing operation is zero.
 18. The device asclaimed in claim 15, wherein the carriage and the second work piececlamped to said carriage are adapted to turn about the longitudinal axisof the second work piece such that the end face thereof assumes aposition relative to the end face of the first work piece such that theangle formed between the transverse axes of each of said work pieces isone of a predetermined value and zero wherein the piston rods of theupsetting cylinder units are arranged to move such that at least one ofthe piston rods is moved at a different speed from that of the otherpiston rods, whereby the carriage and the second work piece clamped tosaid carriage are adapted to turn about the transverse axis of thesecond work piece such that an end face of said second work pieceassumes a position relative to an end face of the first work piece suchthat the angle formed between the vertical axes of each of said workpieces is one of a predetermined value and zero and to turn about thevertical axis of the second work piece such that said second work pieceassumes a position relative to the first work piece such that the angleformed between the longitudinal axes of each of said work pieces assumesone of a predetermined value and zero.
 19. The device as claimed inclaim 15, wherein the upsetting cylinders are pivotally connected attheir ends to the frame structure and to the carriage at separateattachment points, said points positioned relative to one another suchthat a total moment of force exerted on the frame structure during thepressing operation is zero.
 20. The device as claimed in claim 15,whereby the carriage and the second work piece clamped to the carriageare adapted to turn about the vertical axis of the second work piecesuch that the second work piece assumes a position relative to the firstwork piece, wherein the angle formed between the vertical axis of saidwork piece is one of a predetermined value and zero.
 21. The device asclaimed in claim 14, wherein the carriage and the second work piececlamped to said carriage are adapted to turn about the longitudinal axisof the second work piece such that the end face thereof assumes aposition relative to the end face of the first work piece such that theangle formed between the transverse axes of each of said work pieces isone of a predetermined value and zero wherein the piston rods of theupsetting cylinder units are arranged to move such that at least one ofthe piston rods is moved at a different speed from that of the otherpiston rods, whereby the carriage and the second work piece clamped tosaid carriage are adapted to turn about the transverse axis of thesecond work piece such that an end face of said second work pieceassumes a position relative to an end face of the first work piece suchthat the angle formed between the vertical axes of each of said workpieces is one of a predetermined value and zero and to turn about thevertical axis of the second work piece such that said second work pieceassumes a position relative to the first work piece such that the angleformed between the longitudinal axes of each of said work pieces assumesone of a predetermined value and zero.
 22. The device as claimed inclaim 14, wherein the upsetting cylinders are pivotally connected attheir ends to the frame structure and to the carriage at separateattachment points, said points positioned relative to one another suchthat a total moment of force exerted on the frame structure during thepressing operation is zero.
 23. The device as claimed in claim 14,whereby the carriage and the second work piece clamped to the carriageare adapted to turn about a vertical axis of the second work piece suchthat an end face thereof assumes a position relative to an end face ofthe first work piece, wherein an angle formed between the longitudinalaxes of each respective work piece is zero.
 24. The device as claimed inclaim 1, wherein the upsetting cylinders are pivotally connected attheir ends to the frame structure and to the carriage at separateattachment points, said points positioned relative to one another suchthat a total moment of force exerted on the frame structure during apressing operation is zero.